Buying a different stock within 30 days

Apologies if this violates the rules. I'll be reposting this under tax questions.

Here's the background.

I had money invested in VCLT which is an ETF for corporate bonds. Sold that last month (less than 30 days ago) at a loss (long term) and bought a bunch of VOO. Just sold my VOO and purchased SPHY which is similar to VCLT. When I look at the rules for wash sales it says that if I rebuy the same or similar asset I can't use the losses.

My question is, if it's a different ETF is that automatically a different asset or do I need to worry about the fact that they are in similar asset classes?